The use of full-tilt windows have made easier the ability to clean, replace and repair the window sash and other components of the window assembly. Locking devices have been used with full-tilt single and double hung windows to counter the force exerted by a window balance while the window sash is tilted away from the vertical axis of a window jamb or jambliner.
Although conventional locking devices have generally proven effective, they are typically fabricated with numerous components that increase the complexity of assembly and the cost of the device. Additionally, many of such components require frequent replacement due to increased wear and tear. Other conventional locking devices are fabricated of materials of insufficient durability or thickness. Over time, these devices generally suffer from a reduced ability to counter the force of a window balance while the window sash is in a tilted position. As a result, curative measures, such as excessive manipulation of the sash or the use of additional sash pins, are often required to achieve locking. These measures however, typically increase the likelihood of window sash breakage.
Additionally, many locking devices easily disengage from the window sash pin during installation of a window unit in a window frame, adding to the complexity of installation. A window unit typically includes such components as a jamb or jambliner, a spring balance and a locking device. Often a contractor when installing a window unit, will lift the window unit from a rest position without concern as to whether the components are in a position such that disassembly may occur. As a result of such mishandling, the sash pin associated with the locking shoe often disengages from the unit, and the contractor must obtain another sash pin and reconfigure the sash pin and the locking shoe prior to installation. Although locking devices having an integral sash pin can provide relative ease of installation, such devices often make difficult subsequent disengagement of the sash from the device.
Still other locking devices are not easily removed from a jamb or a jambliner after installation. These devices often necessitate removal of the entire window unit when the locking device is in need of repair or replacement.
It is therefore an object of the present invention to provide a locking device that overcomes the above-noted problems of conventional locking devices. Particularly, it is an object of the present invention to provide a locking device of reduced cost and increased reliability comprising a substantially integral, durable locking member that effectively counters the force of a spring balance when a window sash is tilted or removed from the window frame. It is another object of the present invention to provide a locking device that securely retains a sash pin during installation and provides ease of removal of the sash pin and window sash after installation. These and other objects are achieved by the locking device of the present invention.